Fork lift truck



March 31, 1953 F. F-. SUTHERLAND 2,533,260

FORK LIFT TRUCK Filed Jan. 6 1949 v INVENTOR. FREDERICK F. SUTHERLAND.

BY Q W ATTORNEYS Patented Mar. 31, 1953 FORK LIFT TRUCK Frederick F. Sutherland, Cumberland, M(l assignor to Celanese Corporation of America, a

corporation of Delaware Application January 6, 1949, Serial No. 69,436

8 Claims.

This invention relates to fork lift trucks, and relates more particularly to lifting forks adapted for use with said trucks.

As is well known, the use of fork lift trucks permits of important savings to be effected in the handling of objects. However, despite their many advantages, fork lift trucks are of only limited application since they require that the objects being handled be supported on pallets, skids, cleats or in some other special manner. While many proposals have been made to adapt fork lift trucks to handle objects not specially supported, none of these proposals has met with widespread acceptance since they were not suitable for their intended purpose.

It is an important object of this invention to overcome the foregoing and other disadvantages of the prior fork lift trucks, and to provide a fork lift truck which will be especially simple in construction and eflicient in operation.

A further object of this invention is to provide a fork lift truck which will permit objects that are not specially supported to be readily handled.

Another object of this invention is the provision of a. lifting fork, adapted for use on fork lift trucks, which is provided with locating baflies to limit the extent to which said lifting fork may be inserted under an object and which is also preferably provided with a sharp leading edge and rollers or other anti-friction means on its upper surface to permit said lifting forks to be loaded or unloaded more readily.

Other objects of this invention, together with certain details of construction and combinations of parts, will be apparent from the following detailed description and claims.

I have now discovered that various objects, such as packages, containers and the like, which are not specially supported may be handled readily with a fork lift truck by providing the lifting fork thereof with bafiles to limit the extent to which said lifting fork may be inserted under said package. The 'baflles should be positioned so as to permit the package to rest on the lifting fork with its center of gravity over said lifting fork, but with its leading end thereof. In addition, the leading end of said lifting fork is preferably provided across its entire width with a relatively sharp edge which can be inserted readily under a package, and with rollers, or other anti-friction devices on its upper surface, to permit said lifting fork to slide under or to be withdrawn readily from under the package.

A preferred embodiment of my invention is end overhanging the.

illustrated in the accompanying drawing in Fig. 2 is a side elevation of a fork lift truck equipped with the lifting fork shown in Fig. 1 in the loading or unloading position,

Fig. 3 is a side elevation of the fork lift truck shown in Fig. 2 in the carrying position,

Fig. 4 is a side elevation of the lifting fork shown in Fig. l carrying a package, having a base Of small dimensions, and

Fig. 5 is a side elevation of the lifting fork shown in Fig. 2 carrying a package having :a base of large dimensions.

Like reference numerals indicate like parts throughout the several views of the drawing.

Referring now to the drawing, the reference numeral II designates a truck, which is provided with a lifting column I2 on which is mounted the lifting fork indicated generally by the reference numeral I3. The lifting column I2 is constructed and arranged so that it may be tilted forward about 5 degrees from the vertical and tilted backward about 10 degrees from the vertical. In addition, the lifting column I2 is powered to permit the lifting fork I3 to be raised and lowered as desired.

The lifting fork I3 comprises tines I 4, I5 and I6 which are joined to each other at their forward end by means of a plate I1 and at their rear end by means of straps I8 and I9. The plate I1 is set into recesses ZI, 22 and 23 in the tines I 4, I 5, and I6, respectively, so that its upper surface will be flush with the upper surface of said tines. In addition, the plate I I is tapered at 24 to provide a leading edge 25 which is relatively sharp and which may be readily inserted under the edge of a package. The lower surface of the tines I4, I5 and I6 is tapered at 26, 21 and 28 to permit the leading edge 25 of the plate I! to be brought into contact with the floor when the lifting column I2 is tilted forward and the lifting fork I 3 is lowered.

A plurality of freely rotatable rollers 29 are provided between the tines I4, I5 and I6 and are so mounted thereon that they will project to a slight extent above the surface of said tines. Each of the tines I 4 and I6 is provided with a plurality of recesses 3| in which there are mounted for free rotation a plurality of rollers 32 which project above the surface of said tines to the same extent as the rollers 29. By providing the lifting fork I3 with the rollers 29 and 32, the frictional forces during loading and unloading are reduced to a minimum.

The lifting fork i3 is also provided with eating baffles 33 and 34 which limit the extent to which said lifting fork may be inserted under a package. The locating baffle 33 is fastened to arms 35 which are pivotally mounted on stub shafts 36, which shafts are supported in hangers 31 fastened to the strap l8. Similarly, the locating baffle 34 is fastened to arms 38 that are also pivotally mounted on the shafts 36. A hook 39, pivotally mounted in a bifurcated bracket M, is fastened to one of the arms 35 in a position to engage the upper end of the tine i6 and hold the locating bafile 33 and arms 35 in non-operative position. The locating baffle 34 and arms 38 may also be held in non-operative position by means of a hook 42 that is pivotally mounted in a bearing 43 that is fastened to the strap 13 and which engages a slot 44 in said locating bafile.

During operation when a package cs having a base of medium dimensions is being handled, the locating baffle 33 is brought to its inoperative position, as shown in Figs. 2 and 3, leaving the locating baffle 34 in operating position. The lifting column 12 is then tilted forward and the lifting fork i3 is lowered until the leading edge of the plate I1 is in contact with or spaced slightly from the floor. The truck H is then moved forward, and the edge 25 will enter under the package 45. As the truck H continues to move forward the package 45 rides on the rollers 29 and 33 until it strikes the locating baffle 33. The lifting column (2 is then tilted backward and the lifting fork l3 raised to the carrying position as shown in Fig. 3. When it is desired to unload the package 45, the lifting fork i3 is I lowered and the lifting column l2 tilted forward until the edge of said package is brought into contact with the floor. The truck I l is then moved away from the package 45 permitting it to slide off the lifting fork l3.

The locating baffie 34 should be positioned so as to permit the package to rest on the lifting fork l3 with its center of gravity over said lifting fork, but with its end overhanging the end of said lifting fork. riage of the package when the telescopic column I2 is in the carrying position asshown in Fig. 3, but permits the package 45 to be readily unloaded when desired. When handling a package 46 having a base locating bafile 33 is moved into its operative position to restrict still further the extent to which the lifting fork 13 can extend under said package, as shown in Fig. 4. On the other hand, when handling a package 4'! having a base of large dimensions, both of the locating baffles 33 and 34 are raised to inoperative position permitting the lifting fork 13 to extend under said package for substantially its full length, as shown in Fig. 5.

While the lifting fork l3 shown in the accompanying drawing is provided with two locating baffles 33 and 34, it may obviously be provided With a smaller or larger number of baflies depending on the total length of the tines and the number of different sizes of packages being handled.

It is to be understood that the foregoing detailed description is given merely by way of illustration and that many variations may be made therein without departing from the spirit of my invention. Having, described my invention, what I desire to secure by Letters Patent is:

1. In a fork lift truck, the combination with This insures the safe carof small dimensions, the w ill a lifting column which may be tilted from the vertical, of a lifting fork having a sharp leading lower edge extending across its entire width, anti-friction means in the upper surface of said lifting fork, a plurality of separately and selectively operable locating baffles to limit the extent to which said lifting fork may be inserted under an object and means for holding said 10- eating baffles in non-operative position.

2. In a lifting fork adapted for use with fork lift trucks, the combination with a plurality of tines, of a plate having a sharp leading lower edge set into the forward ends of said tines so that the upper surface of said plate is flush with the upper surface of said tines, a plurality of rollers extending above the upper surface of said tines and mounted for free rotation between said tines, and a plurality of rollers extending above the upper surface of said tines and mounted for free rotation in said tines.

3. In a lifting fork adapted for use with fork lift trucks, the combination with a plurality of tines, of a locating baffle for limiting the extent to which said lifting fork may be inserted under an object, a plurality of pivotally mounted arms supporting said locating baffle whereby said 10- cating baffle may be moved to non-operative position, and means for holding said locating baflle in non-operative position.

4. In a lifting fork adapted for use with fork lift trucks, the combination with a plurality of tines, of a plurality of locating baffles for limiting the extent to which said lifting fork may be inserted under an object, and a plurality of pivotally mounted arms independently supporting said locating baffles whereby said locating bafiles may be selectively moved to non-operative position.

5. In a lifting fork adapted for use with fork lift trucks, the combination with a plurality of tines, of a plurality of locating baffles for limiting the extent to which said lifting fork may be inserted under an object, a plurality of pivotally mounted arms independently supporting said 10- eating baffles whereby said locating baffles may be selectively moved to non-operative position, and means for holding said locating baffles in non-operative position.

6. In a lifting fork adapted for use with fork lift trucks, the combination with a plurality of tines, of a plate having a sharp leading lower edge set into the forward ends of said tines so that the upper surface of said plate is flush with the upper surface of said tines, a plurality of anti-friction means extending above the upper surface of said tines, and a locating baffle for limiting the extent to which said lifting fork may be inserted under an object.

7. In a lifting fork adapted for use with fork lift trucks, the combination with a plurality of tines, of a plate having a sharp leading lower edge set into the forward ends of said tines so that the upper surface of said plate is flush with the upper surface of said tines, a plurality of rollers extending above the upper surface of said tines and mounted for free rotation between said tines, a plurality of rollers extending above the upper surface of said tines and mounted for free rotation in said tines, a plurality of locating baffles for limiting the extent to which said lifting fork may be inserted under an object, a plurality of pivotally mounted arms independently supporting said locating baffles whereby said 10- cating baffles may be selectively moved to nonoperative position, and means for holding said locating baffles in non-operative position.

8. In a lift truck, load supporting means having a sharp leading edge extending substantially across the front thereof and having an upper surface adjacent to said leading edge, rotatable anti-friction means mounted on said load supporting means and so aligned with said upper surface that a package may be slid on said upper surface and onto said anti-friction means, means for lifting said load supporting means, tilting means operable to tilt said load supporting means forward so that said leading edge may engage and move under a package with the package riding onto said anti-friction means and operable to tilt said load supporting means backward so that the package may be carried thereby, and locating bafile means constructed and arranged to provide a plurality of positions limiting the extent to which said load supporting means may be inserted under the package.

FREDERICK F. SUTHERLAND.

6 REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Lapham Apr. 3, 1951 

